1. Field of the Invention
The present invention relates to a polarizing film used for various image display units such as a liquid crystal display (hereinafter, abbreviated as ‘LCD’).
2. Description of the Related Art
LCDs have been used widely for, e.g., desk calculators, electronic clocks, personal computers, word processors, and instruments of automobiles and machines. Recently, demand for LCDs has been increased rapidly, leading to a further requirement for large, light-weighted and thin panels.
In general, such a LCD includes a polarizing plate as a laminate of a polarizer and a transparent protective layer for visualizing a variation in orientation of its liquid crystal. The polarizing plate has a great influence on the display characteristics of the LCD. However, conventional polarizing plates has a problem of instability in size, i.e., the size of the polarizing plate can vary considerably under a heated or humidified condition. The variation in size will exert a force on the polarizing plate, thereby the liquid crystal panel will be warped during a use of the liquid crystal display. Consequently, the display characteristics deteriorate, for example, the transmittance of the in-plane panel varies.
It is required to suppress variation in size of the polarizing plate for solving the problem. However, since typical polarizing plates currently used are made of plastic films, such variations in size are difficult to prevent perfectly.